Although integrate circuit (IC) processor speeds have continued to increase rapidly, electrical interconnect speeds have not increased at the same rate. Thus, electrical interconnects create a bottleneck that limits the ultimate capacity of the associated processors. Recently, optical interconnects have been introduced as a solution to address most; if not all, of the problems associated with electrical interconnects. Optical interconnects may be used to allow board-to-board, chip-to-chip, and on-chip optical communication, which may provide benefits including low latency, high throughput, high density, high bandwidth, and integration with existing silicon technology.
For chip-to-chip or board-to-board optical communication of signals, an IC package mounted on printed circuit board may include a photoreceiver die that faces the printed circuit board to receive light signals being communicated by or through the circuit board. Typically, the substrate of the IC package includes three or more layers, each comprising a copper trace or other conductive layer. However, as small consumer electronics such as mobile phones and personal digital assistants (PDAs) continue to proliferate, the need for smaller IC chip packages has increased. Thus, it would be desirable to provide reduced-sized IC packages that include one or more photoreceivers for chip-to-chip or board-to-board optical communication of signals.